Soluble intercellular adhesion molecule-1 concentrations in patients with subacute thyroiditis and in patients with Graves' disease with or without ophthalmopathy

DNA Methylation in Autoimmune Thyroid Disease

Graves disease and Hashimoto disease form part of the spectrum of autoimmune thyroid disease (AITD), to which genetic and environmental factors are recognized contributors. Epigenetics provides a potential link between environmental influences, gene expression, and thyroid autoimmunity. DNA methylation (DNAm) is the best studied epigenetic process, and global hypomethylation of leukocyte DNA is reported in several autoimmune disorders. This review summarizes the current understanding of DNAm in AITD. Targeted DNAm studies of blood samples from AITD patients have reported differential DNAm in the promoter regions of several genes implicated in AITD, including TNF, IFNG, IL2RA, IL6, ICAM1, and PTPN22. In many cases, however, the findings await replication and are unsupported by functional studies to support causal roles in AITD pathogenesis. Furthermore, thyroid hormones affect DNAm, and in many studies confounding by reverse causation has not been considered. Recent studies have shown that DNAm patterns in candidate genes including ITGA6, PRKAA2, and DAPK1 differ between AITD patients from regions with different iodine status, providing a potential mechanism for associations between iodine and AITD. Research focus in the field is moving from candidate gene studies to an epigenome-wide approach. Genome-wide methylation studies of AITD patients have demonstrated multiple differentially methylated positions, including some in immunoregulatory genes such as NOTCH1, HLA-DRB1, TNF, and ICAM1. Large, epigenome-wide studies are required to elucidate the pathophysiological role of DNAm in AITD, with the potential to provide novel diagnostic and prognostic biomarkers as well as therapeutic targets.

Risk Factors of Thyroid Eye Disease

OBJECTIVE

To examine risk factors that might be associated with thyroid eye disease (TED) in patients with Graves' disease (GD), which may guide physicians in the prevention and management of TED.

METHODS

Medline and Embase were searched for articles discussing risk factors of TED. Comparisons were made between GD patients with and without TED, and between active and inactive TED GD patients. Weighted mean differences (WMDs) and odds ratios (ORs) were determined for continuous and dichotomous outcomes, respectively. Results were pooled with random effects using the DerSimonian and Laird model.

RESULTS

Fifty-six articles were included in the analysis. Smoking, inclusive of current and previous smoking status, was a significant risk factor for TED (OR: 2.401; CI: 1.958-2.945; P < .001). Statistical significance was found upon meta-regression between male sex and the odds of smoking and TED (β = 1.195; SE = 0.436; P = .013). Other risk factors were also examined, and patients with TED were significantly older than those without TED (WMD: 1.350; CI: 0.328-2.372; P = .010). While both age (WMD: 5.546; CI: 3.075-8.017; P < .001) and male sex (OR: 1.819; CI: 1.178-2.808; P = .007) were found to be significant risk factors for active TED patients compared to inactive TED patients, no statistical significance was found for family history, thyroid status, cholesterol levels, or body mass index.

CONCLUSION

Factors such as smoking, sex, and age predispose GD patients to TED, and TED patients to active TED. A targeted approach in the management of GD and TED is required to reduce the modifiable risk factor of smoking.

High circulating levels of sICAM-1 and sVCAM-1 in the patients with Hashimoto's thyroiditis

OBJECTIVE

To investigate whether soluble intercellular adhesion molecule-1 (sICAM-1) and soluble vascular cell adhesion molecule-1 (sVCAM-1) levels are increased in euthyroid patients with Hashimoto's thyroiditis (HT) and whether they are associated with thyroid autoimmunity and metabolic parameters.

DESIGN

Cross-sectional.

SUBJECTS AND METHODS

In total, 80 euthyroid patients with HT and 80 age- and body mass index (BMI)-matched control participants were included. Serum sICAM-1, sVCAM-1, free triiodothyronine (fT3), free thyroxine (fT4), thyroid-stimulating hormone (TSH), thyroid peroxidase antibody (anti-TPO), thyroglobulin antibody (anti-TG), fasting blood glucose (FBG), insulin, and lipid levels and homeostasis model assessment for insulin resistance (HOMA-IR) were assessed in all participants.

RESULTS

The patients with HT had significantly higher levels of sICAM-1 and sVCAM-1 than controls (both p < 0.001). The difference was sustained after adjustment for TSH and levothyroxine use. Regression analysis demonstrated that sICAM-1 was related to anti-TPO (p < 0.001), and sVCAM-1 was related to both anti-TPO and-TG (p < 0.001 and p = 0.03, respectively); this relationship was sustained after adjustment for age and BMI. Although FBG and HOMA-IR were higher in the HT group, logistic regression analysis revealed that there was no effect of anti-TPO, anti-TG, sICAM-1, sVCAM-1, and C-reactive protein (CRP) on the occurrence of high FBG and high HOMA-IR.

CONCLUSION

sICAM-1 and sVCAM-1 levels were significantly elevated in the patients with euthyroid HT and correlated closely with thyroid autoimmunity. However, soluble adhesion molecules had no relation with glucose metabolism parameters in the HT patients.

Insulin sensitivity, plasma adiponectin and sICAM-1 concentrations in patients with subclinical hypothyroidism: response to levothyroxine therapy

Subclinical hypothyroidism is associated with an increased risk of atherosclerosis. The aim of this study was to investigate the concentration of plasma soluble intercellular adhesion molecule-1 and adiponectin in relation to insulin sensitivity in patients with subclinical hypothyroidism and to estimate if L-thyroxine treatment had an influence on these parameters. 13 women with subclinical hypothyroidism and 14 euthyroid controls were included in the study. A physical examination was conducted, hyperinsulinemic euglycemic clamp and plasma soluble intercellular adhesion molecule-1, adiponectin and lipids profiles were measured at baseline in both groups and in the group with subclinical hypothyroidism the above procedures were performed after L-thyroxine therapy (mean time of treatment 5.0 months) in stable euthyroid state. Insulin sensitivity and adiponectin were not different at baseline in the two studied groups. Plasma soluble intercellular adhesion molecule-1 concentration was significantly higher in the patients with subclinical hypothyroidism (P = 0.011). The comparison of lipids profiles revealed that only LDL-cholesterol concentration was higher (P = 0.011) in the group with subclinical hypothyroidism. After therapy, we observed an improvement of insulin sensitivity (P = 0.012) and a decrease of plasma glucose (P = 0.019) and soluble intercellular adhesion molecule-1 (P = 0.01), whereas adiponectin concentration remained unchanged. We concluded that L-thyroxine treatment in patients with subclinical hypothyroidism might exert a beneficial effect by reducing cardiovascular risk factors.

Smoking and disease severity are independent determinants of serum adhesion molecule levels in Graves' ophthalmopathy

Adhesion molecules play a key role in autoimmune disorders, and serum concentrations of soluble adhesion molecules are increased in Graves' ophthalmopathy (GO). Whether this is due to the strong association with smoking is unknown. It is also not known if the severity or activity of GO determine the serum levels of adhesion molecules. We measured serum concentrations of sICAM-1, sVCAM-1 and sELAM-1 in 62 euthyroid Graves' patients with untreated GO, in 62 healthy controls matched for sex, age and smoking habits, and in 26 euthyroid Graves' patients without GO. GO severity was assessed by the Total Eye Score and the activity by the Clinical Activity Score. Adhesion molecules were measured by highly sensitive ELISAs. GO patients had higher levels than controls (median values in ng/ml with range): sICAM-1 300 [171--575] versus 244 [119--674], P < 0.001; sVCAM-1 457 [317--1060] versus 410 [238--562], P < 0.001; and sELAM-1 61 [19--174] versus 53 [23--118], P = 0.021. Euthyroid Graves' disease patients without GO had levels similar to controls: sICAM-1 273 138--453), sVCAM-1 386 [260--1041] and sELAM-1 46 [22--118]. Smoking had an independent effect and was associated with higher levels of sICAM-1 and lower levels of sVCAM-1 in both GO patients and controls; sELAM-1 levels were comparable. In the 62 GO patients, sICAM-1 correlated significantly with severity of eye disease (r = 0.40, P = 0.002). No correlation was found with the duration of GO, the Clinical Activity Score or TBII levels. Multivariate analysis of all 150 subjects showed that the presence of GO and smoking are independent determinants of sICAM-1 and sVCAM-1 concentrations. In GO patients, the Total Eye Score was a stronger determinant than smoking. It is concluded that (i) smoking is associated with increased sICAM-1 and decreased sVCAM-1 levels; (ii) independent from smoking, euthyroid GO patients have higher levels of sICAM-1, sVCAM-1 and sELAM-1 than patients with euthyroid Graves' disease or healthy controls; (iii) the major determinant of sICAM-1 in GO patients is the severity of their eye disease.

Serum levels of tumor necrosis factor-alpha, soluble intercellular adhesion molecule-1, soluble vascular cell adhesion molecule-1, and soluble interleukin-1 receptor antagonist in patients with thyroid eye disease undergoing treatment with somatostatin analogues

The aim of this prospective, randomized study was to investigate the serum levels of tumor necrosis factor-alpha (TNF-alpha), soluble intercellular adhesion molecule-1 (sICAM-1), soluble vascular cell adhesion molecule-1 (sVCAM-1), and soluble interleukin-1 receptor antagonist (sIL-1RA) in patients with thyroid eye disease (TED) before and 1 and 3 months after treatment with somatostatin analogues (SM-a). Thirty patients, all with signs and symptoms of TED, were studied. Twenty-two patients (13 females) had active eye disease with a clinical activity score (CAS) > or = 4 (patients with active disease [PA]) and 8 patients (5 females) had inactive TED with CAS < or = 3 (patients with inactive disease [PI]). All PA patients had a positive orbital octreoscan, whereas PI patients had a negative one. Fifteen patients from the PA group were selected randomly and received SM-a (PA-S subgroup), while the remaining 7 patients were used as control subgroup (PA-C), received neither therapy, nor placebo. From the 15 patients who received SM-a (PA-S), 6 received octreotide (OCT) and 9 lanreotide (LRT). TED was reevaluated using the CAS 1 and 3 months after the initiation of SM-a treatment. Ten healthy individuals (6 females) were used as controls (group C). We found an increase in the basal levels of TNF-alpha (14.2 +/- 7.1 pg/mL), sICAM-1 (809.1 +/- 167.0 ng/mL), and sIL-1RA (542.1 +/- 259.0 pg/mL) in PA patients as a total group compared with the PI (1.6 +/- 1.9, 676.8 +/- 73.4, 267.6 +/- 152.8, respectively) group and C (1.9 +/- 1.4, 598.0 +/- 126.2, 258.6 +/- 155.1, respectively). The basal levels of TNF-alpha (13.3 +/- 8.3 pg/mL) and sIL-1RA (533.7 +/- 308.9 pg/mL) in PA-S as well as in PA-C (16.0 +/- 2.9, 560.2 +/- 107.3, respectively) subgroups were also increased compared with PI patients and C (1.9 +/- 1.4 and 258.6 +/- 155.1, respectively). The same was true for sICAM-1 when baseline levels compared with C (817.1 +/- 187.3 and 791.9 +/- 123.5, respectively vs. 598.0 +/- 126.2 ng/mL). After SM-a, serum levels of sICAM-1 and sVCAM-1 were decreased significantly 1 (781.2 +/- 205.9, 1,193.5 +/- 511.8 ng/mL) and 3 months (786.8 +/- 199.6, 1,122.1 +/- 225.3 ng/mL) after the initiation of treatment. In conclusion, serum levels of TNF-a, sICAM-1, and sIL-1RA were elevated in patients with active TED compared to controls. Furthermore, sICAM-1 and sVICAM-1 levels declined during the treatment with SM-a in patients with active TED.

Serum levels of adhesion molecules in children and adolescents with immune and non-immune thyroid diseases

Serum levels of sICAM-1, sVCAM-1 and sP-selectin were determined in patients with Graves' disease before and after 8 weeks and 24 months of methimazole therapy, in levothyroxine suppressed patients with non-toxic nodular goiter, and in a group of healthy controls, to elucidate the relationship to circulating antithyroid antibodies and possible role of soluble adhesion molecules as markers of inflammatory activity. sICAM-1, sVCAM-1, and sP-selectin in patients with untreated hyperthyroidism were markedly elevated compared with controls. After 8 weeks of methimazole treatment, the concentrations of these molecules dropped, but were still significantly higher than in healthy children. In patients with clinical and biochemical remission after 24 months of therapy, sICAM-1 values were on the verge of significance, but still higher than in the control group, whereas serum levels of sVCAM-1 and sP-selectin had normalized. Slightly higher serum sICAM-1 values were observed in patients with non-toxic nodular goiter compared with healthy children.

[Endocrine orbitopathy 1998]

BACKGROUND

Ophthalmopathy is the most common extrathyroidal manifestation of Graves' disease, also called thyroid-associated ophthalmopathy.

CLINICS

This autoimmune disorder is characterized by a lymphocyte infiltration of the retrobulbar space. Activated T cells react with the target organ and secrete cytokines, leading to accumulation of glycosaminoglycans, interstitial edema of the peri- and retrobulbar tissue and enlargement of the extraocular muscles. During the inflammatory stage, the increased orbital pressure results in the clinical manifestation of the eye disease.

DIAGNOSIS AND TREATMENT

Thus, therapeutic immunosuppression is often used initially, and by suppressing inflammatory changes, it can result in subjective and objective improvement of the thyroid eye disease. In recent years, new pathogenetic aspects and clinical randomized trials led to modified therapy concepts.

CONCLUSION

Interdisciplinary management is recommended for rapid diagnosis and effective therapy of patients with thyroid-associated ophthalmopathy.

Soluble intercellular adhesion molecule-1 (sICAM-1) concentrations in Graves' disease patients followed up for development of ophthalmopathy

It is commonly recognized that a few patients with Graves' disease (GD) develop an overt ophthalmopathy, although most of them show subclinical extraocular muscle enlargement by appropriate imaging techniques. At present, it is not possible to identify the subgroup of GD patients with subclinical retroorbital connective involvement. Recently, it has been shown that increase of soluble intercellular adhesion molecule-1 (sICAM-1) serum levels is correlated to clinical activity score in active Graves' ophthalmopathy (GO) patients with or without hyperthyroidism, suggesting that sICAM-1 serum values could reflect the degree of ocular inflammatory activity. The aim of this longitudinal study was to evaluate sICAM-1 serum levels in GD patients without clinical ophthalmopathy and to assess their possible relationship with occurrence of GO. We measured sICAM-1 serum levels in 103 initially hyperthyroid GD patients without clinical ophthalmopathy and in 100 healthy subjects. All patients were treated with methimazole for 2 yr. Sera were collected from all patients before treatment and then monthly for the first 6 months of therapy, every 2 months in the following 6 months, and finally at the end of the follow-up study. Patients developing GO were excluded from the follow-up at the onset of ophthalmopathy. During the follow-up 17 GD patients (16.5%, group 1) developed overt eye involvement (14 as active inflammatory ophthalmopathy and 3 as ophthalmopathy without clinical retroorbital connective inflammation) and 86 (83.5%, group 2) did not. At start of the study, the mean of sICAM-1 serum concentrations did not differ significantly between the 2 groups, but it was significantly higher than in controls in both groups. No significant correlation between serum sICAM-1 concentrations and free thyroid hormone levels was found in the 2 groups of patients. During the follow-up study, a further increase of sICAM-1 serum levels was observed in 12 of the 14 patients (85.7%) of group 1 who developed active inflammatory ophthalmopathy not only at the onset but also before clinical GO appearance. On the contrary, the 3 patients of group 1 that developed ophthalmopathy without clinical retroorbital inflammation did not show any further increase of sICAM-1 levels at every time of follow-up in comparison with the starting values, even if their sICAM-1 levels were always higher than in normal controls. Finally, group 2 patients showed significantly decreased sICAM-1 levels throughout the follow-up period when compared with the starting values, although they were still significantly higher than in controls. These results indicate that a further increase of sICAM-1 serum levels before the onset of clinical ophthalmopathy may be a marker of subclinical retroorbital connective inflammation in GD patients. Therefore, our study suggests that serial determinations of sICAM-1 serum levels could help to identify and trace at the right time those GD patients prone to developing active inflammatory ophthalmopathy.